Centrifugal speed governor



Feb. 4, 1941. D. F. W 'RNE'R- 2,230,736

CENTRIFUGAL SPEED GOVERNOR Filed Aug 31, 9:58

Invefitor: Dohald FTWarner;

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Patented Feb. 1, 1941 UNITED STATES PATENT OFFICE CENTBIFUGAL SPEED GOVERNOR Donald F. Warner, Swampscott, Mass assignor to General Electric Company, a corporation of New York Application August 31, 1938, Serial N 0. 227,782

7 Claims. (01.264-) spring. If such governor is used in connection with prime movers or motors operated 'at variable speed, the available regulating effortdrops with decreasing'speed of the prime mover. Accurate control with this type of governor has been ob- I ficing sensitivity at low speeds.

For a consideration of whatI believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawing.

In the drawing, Fig. 1 illustrates a perspective view of a governor embodying my invention; Fig. 2 is a sectional view of the governor shown in Fig. l; and Fig. 3 is an explanatory view of certain characteristics of the governor.

The governor comprises a fiyweight support which is in the form of a cylinder III with a bottom I I and a hub I2. Diametrically opposite portions of the cylinder are cut out to form large openings I3. The hub I2 serves as a connection to a spindle for rotating the governor about the axis of the cylinder. Brackets I4, I5, I6, I1 are secured to the open portions of the cylinder by means of welds I8. The brackets I4, I5 are connected by a cross-member or plate I9 and the brackets I6, II are connected by abplate 20, these plates being located parallel to a plane through the axis of the cylinder and actto' reinforce the latter. Two flyweights 2|, 22 are fulcrumed' on the brackets. Each flyweight has a cross-pin 23 securely fastened to it and supported by roller or so-called antifriction bearings 24 and 25 on the brackets I5, I! and [4, I5 respectively. The

roller-bearings are retained in position by plates 26 securedto the brackets by screws 21. The flyweight M has an arm 28 carrying a roller 29 in engagement with the lower end portion of an arm 30 of the fiyweight 22. The roller 29' engages the arm 30 in the approximate center of rotation of the governor. The upper'end portion of the arm 30 forms a conical bearing 3| connected by a rod 32 to a controlled element 33, in the present instance a pilot valve with oil dump openings 34. The upper circumference of the sleeve forms a port when in operative conjunction with its companion bushing (not shown). The sleeve is maintained in engagement with and .driven by the governor by means including a ten- 7 sion spring 35. The lower end of the spring 35 engages a support 35a which has diametrically opposite brackets 35b held on end portions of a pin 350. The latter also carries the aforementioned roller 29. The arms of the flyweights have downwardly projecting portions 36 and 31 respectively which are connected or biased towards each other by means of a tension spring 38. The ends of the spring are fastened to the portions 36 and 31 of the flyweight arms by means including screws 39 and 40 respectively.

During rotation of the cylinder III the flyweights 2 I, 22 are forced outwardly by centrifugal action against the biasing force of the governor spring 38 into a position indicated in Fig. 2. At rest, that is, while out of operation, the flyweights 2 I,

22 are forced inward against stops M and 42 respectively. These stops are in the form of pins connecting the outer portions of the lugs I4, I6 and I5, I! respectively. The stops M, 42 have projections 43 and 44 respectively'in the direction of the arm projection 36 and 31 to act as stops as the governor reaches a certain maximum speed.

Regarding the regulating action, increase in speed causes outward movement of the flyweights whereby the engaging arms are moved downward and cause downward movement of the pilot valve sleeve 33.

The explanatory view of Fig. 3 shows the flyweight2l with its arm 28 and the roller 29 in the position of rest. The flyweight is supported on bearings 24, 25'which constitute a fulcrum having a center 45. The center of the fulcrum is connected by a' dashed line 46 with the center 41 of the roller 29 and by another dashed'line 48 with a point 49, the latter being the point of application of the spring force, that is, the force exerted by the spring 38 on the flyweight. The fulcrum center is connected by another dashed line 50 with a point 5| which constitutes the center of mass of the fiyweight. The center of mass 5I at rest is located a distance A below the horizontal through the fulcrum center 45 and a distance R from the center of rotation 52. The

point 49 is located a distance 13 below the horizontal through the 'fulcrum center 45 and a distance s from the center of rotation, the distance .9 constituting one half the length of the horizontally disposed governor spring 38. Furthermore, the lines 50 and 48 form angles a and ,3 respectively with the horizontal through the fulcrum center 45 and these angles at rest approximate about 45. From another viewpoint, the point of application 49 of the spring force is preferably located below and radially inward of the fulcrum center 45 and on the line 48 subtended about 45 from the horizontal line through the fulcrum center 45. The center of mass 5| is located at a level intermediate the centers 45 and 49 and radially outside the fulcrum center 45, preferably on a line 50 subtended approximately 45 from the horizontal through the fulcrum center 45. The center 41 of the roller 29 is located above the horizontal a distance which is preferably equal one half the total governor travel so that at maximum speed the center 41 of roller 29 is located an equal distance below the horizontal through the fulcrum center 45. The lines 46, 48 also have been shown dash-dotted in several operating positions of the governor. All of these lines move about the fulcrum center in clockwise direction with increasing speed.

As pointed out above, the points 5| and 49 are both located below the fulcrum 45. The term "below? is relative and used with respect to the arrangement as shown in the drawing. More generally, the points 5| and 49 are both spaced from and located on the same side of the plane of rotation through the fulcrum 45 and in addition the point 5| is located radially outward and the point 49 radiallyinward of the fulcrum 45, that is, the distance of the point 49 from the center of rotation is smaller and that of the point 5| is larger than the distance of the fulcrum 45 from the center of rotation or the distance between the points 49 of the flyweights is smaller and theldistance between the centers of mass 5| is larger than the distance between the fulcrums 45 of the fiyweights. Also, as pointed out above, the distance of the point 41 which is the center of the roller 29 at maximum speed from the plane of rotation through the fulcrum 45 is about equal the distance of the point 41 from this plane at rest, or, from another viewpoint, the point 41 normally moves from a certain distance above the plane of rotation through the fulcrum 45 to about an equal distance below said plane.

With the arrangement of centers as above described the radius R, that is, the distance of the center of mass from the center of rotation, increases slowly with increase in speed. The arm A decreases and the arm B increases with increase in speed. The spring length 2s increases with increase in speed although not in straight line relation to the angular deflection of the weights. These effects combine to give the desired governor characteristics, permitting accurate control at a speed range of 5:1 and higher. The force-travel curve of this governor is nearly a straight line through the zero point and shows great strength, particularly at low speed at comparatively small spring loads. The angle subtended by the intersection of the spring force-travel line with the weight force-travel line at a constant speed is relatively great, indicating great governor strength and abilityto overcome small disturbances to equilibrium without substantial error.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Centrifugal type speed governor for operation at wide speed ranges comprising two flyweights for rotation about the vertical axis of rotation of the governor and having arms with end portions engaging each other near the center of rotation for moving an element to be controlled in response to speed changes, a support forming a fulcrum for each arm, and a horizontal spring connected between the flyweights to bias them against the action of centrifugal force, each flyweight having a center of mass located at rest radially outward and below the .center of the fulcrum, and the point of application of the spring force on the flyweights being located radially inward of and below the center of the fulcrum. I

2. Centrifugal type speed governor for operation at wide speed ranges comprising two flyweights for rotation about the vertical axis of rotation of the governor and having arms with end portions engaging each other near the center of rotation for moving an element to be controlled in response to speed changes, a support forming a fulcrum for each arm and a horizontal spring connected between the flyweights to bias them against the action of centrifugal force, each 'fiyweight being shaped to have a center of mass located when at rest radially outward of the center of the fulcrum and approximately on a line through the center of the fulcrum subtending an angle of 45 from the horizontal through the fulcrum center and each end of the spring being connected to a point of the flyweights located radially inward of the center of the fulcrum on a line through the center which line is subtended at an angle of about 45 from the horizontal through said center.

3. Centrifugal type speed governor for operation at wide speed ranges comprising two flyweights for rotation about the vertical axis of rotation of the governor and having arms with end portions engaging each other near the center of rotation for moving an element to be controlled in response to speed changes, a support forming a fulcrum for each arm, said fulcrum having a center located at a level below the point of engagement of the arm while at rest, and a horizontal spring connected between the flyweights to bias them against the action of centrifugal force, each flyweight having a center of mass located at rest radially outward and below the center of the fulcrum, and the point of application of the spring force on the flyweights being located radially inward of and below the center of the fulcrum.

4. Centrifugal type speed governor for operation at wide speed ranges comprising two fly- .weights for rotation about the vertical axis of rotation of the governor and having arms extending inward towards the axis of rotation,

one arm having an end portion with a roller,

the other arm having an end portion near the axis of rotation with a lower surface in engagement with the roller and an upper surface forming a pivot bearing for connection with an element to be controlled, means for rotating the flyweights and forminga fulcrum support for each of them, and a horizontal spring connected to points of the flyweights located at rest below and inward the center of the fulcrums, each flyweight having a center of mass located radially outward of the center of thefulcrum and at a level intermediate those of its fulcrum and the point of application of the spring force.

5. Centrifugal type speed governor for operation at wide speed ranges comprising a cylinder with openings in diametrically opposite wall portions and a bottom with a hub for connection to a drive spindle, two plate members secured to the openings in parallel relation to a plane through the axis of the cylinder to form brackets outside the cylinder, two fiyweights fulcrumed on the brackets and having arms with end portions engaging each other near the axis of the cylinder, each flyweight having a projection, a spring connected to the projections to bias the flyweights against the action of centrifu'gal force, the fiyweights having a center of mass located at a distance from the plane of rotation through the center of the fulcrum which distance decreases gradually with increasing speed, the spring being connected to a point of the projection located at a distance from said plane through the center of thefulcrum which distance increases gradually with increasing speed.

6. Centrifugal type speed governor foroperation within wide speed ranges comprising two flyweights having arms with end portions engagingeach other near the center of rotation for moving an element to be controlled in response ,to speed changes, a support forming a fulcrum for each arm, and a spring connected between'the flyweights to bias them against the action of centrifugal force and subject to increased tension upon increased speed, the centers of mass and the points of application of the spring being spaced from and located on the same side of the plane of rotation through the fulcrum and the distance between the points of application of the spring being smaller and the distance between the centers of -mass being larger than the distance between the fulcrums.

'7. Centrifugal type speed governor for operation within wide speed ranges comprising two flyweights having arms with end portions engaging each other, a support forming fulcrums for the arms, the point of engagement of the arms being spaced a certain distance from one side of the plane of rotation through the fulcrums at rest and about a similar distance from the opposite sides of said plane at full speed, and a spring subject to increased tension upon increased speed being connected between the flyweights to bias them against the action of centrifugal force, the centers of mass and the points of application of the spring being spaced from and located on the same side of the plane of rotation through the fulcrum and the distance between the points of application of the spring being smaller and the distance between the'centers of mass being larger than the distance between the fulcrums.

DONALD F. WARNER. 

